1. Field of the Invention
This invention relates, in general, to the use of muzzle-loading firearms. More specifically, this invention relates to the design and manufacture of projectiles to be used in such firearms.
2. Related Art
To function most effectively, muzzle-loading firearms preferably involve the use of a bullet in conjunction with some type of wad or gas check member. Throughout the history of such firearms, various configurations that embrace this design principle have been utilized. The wad or gas check is used to secure the bullet properly within the bore without significant deformation of the bullet, and to prevent the escape of forward thrusting gases around the bullet upon firing the firearm. Prior to the use of wads or gas checks, a malleable lead bullet, with a diameter necessarily greater than that of the bore of the firearm, was ram-rodded down the barrel. In this manner, the bullet was frictionally secured in place over the powder charge and engaged with the rifling of the bore, but often malformed when being so placed.
The use of sabots or wrappers was later introduced to facilitate another mechanism of securing the bullet in place. These devices surround a sub-caliber bullet to engage the rifling and secure the bullet without requiring the deformation of a large diameter bullet. When the firearm is discharged the interaction between wrapper and rifling imparts spin to the bullet. C. T. James and A. Ball have obtained U.S. Pat. Nos. 34,950 and 405,690, respectively, for such wrapper-type devices.
D. D. Williams, U.S. Pat. No. 35,273, and G. P. Ganster, U.S. Pat. No. 43,017, have acquired patents for inventions in which the wad was directly attached to the bullet for use in muzzle-loading firearms.
Significant reductions in the efficiency of such firearms often result from destructive interactions between the bullet and bore. When wrappers are used to surround the bullet, the positioning of the wrapper between the bullet and bore may affect the ballistic qualities of the shot. In the case of large-diameter bullets, the scoring and deformation of the projectile that results from the loading process may affect the discharge of the bullet from the bore as well as the in-flight aerodynamics. Kearns, U.S. Pat. No. 5,458,064 provides a gas check member for use with sub-caliber bullets. The diameter of this gas check slightly exceeds that of the bore. The gas check is frictionally attached rearward of the bullet and is constructed of deformable, but durable, plastic. However, where the gas check member does not detach from the bullet, the velocity and accuracy of the shot may be significantly reduced.
Therefore, there is a need for a frictionally attached gas check for use in muzzle-loading firearms that is designed to quickly and reliably detach from the bullet upon firing.
The present invention provides a gas check member for use in muzzle-loading firearms. The gas check member is designed to participate in the loading and firing process such that the loading of such firearms is simple, fast, and effective.
In addition to serving its gas check function, the invented gas check member is designed to secure the bullet in place within the bore and prevent moisture from contacting the powder once the projectile is secured. All this must be accomplished simply and without interfering with the trajectory of the bullet upon firing.
The gas check member comprises a generally cylindrical element with a maximum diameter slightly exceeding that of the bore, which is preferably constructed of a resilient plastic material. The present invention is designed for use with a bullet. The diameter of the gas check member varies according to the diameter, or caliber, of the bullet and bore. The bullet typically comprises a solid cylindrical, ogive or blunted ogive element that tapers in the direction of its forward end and includes at its back end an engaging means. Such bullets are often constructed of lead or another suitable material with a maximum diameter slightly smaller than the bore. The gas check member is located rearward of the maximum diameter of the bullet where it is frictionally attached by the engaging means. Preferably, the gas check member does not surround the bullet.
Upon firing, the gas check member prevents rapidly expanding gases, produced by the ignition of the powder, from escaping around the bullet. These gases impart the necessary forward thrust to the projectile; therefore, minimizing the escape of these gases is beneficial to efficient discharge of the bullet from the barrel of the firearm. The gas check member is designed to corral these propellant gases and transmit a distributed force to the projectile that ejects the bullet from the barrel. A substantial portion of the invented gas check detaches from the bullet upon firing to avoid inhibiting the trajectory of the bullet after its exit from the barrel.
The mechanism of detachment involves the fracture of the gas check member at its forward end along a connective band between the engaging member and the outer skirt. The gas check is engineered to rupture along this annular disk under the force of the gases rushing towards the uncapped distal end of the barrel. Upon exiting the barrel, the skirt of the gas check separates from the bullet allowing the bullet to continue, unimpeded, toward the target.